The present invention relates to automatic transmission systems and, more particularly, to a solenoid switch valve for Chrysler 41TE/42LE transaxles.
A common problem with the Chrysler 41TE/42LE (hereinafter “Chrysler”) transaxles is the failure of the torque converter clutch piston and its friction ring material due to erratic torque converter clutch control. This hydraulic control failure is often caused by a malfunctioning solenoid switch valve assembly within the valve body of the transaxle.
With reference to the drawings herein, the original equipment manufacture (hereinafter “OEM”) solenoid switch valve assembly 100 (i.e. SOL SW VALVE) determines whether the low/reverse lock-up solenoid is going to operate the low/reverse apply circuit (FIG. 1) or, alternatively, the lock-up apply circuit (FIG. 2). Because the solenoid switch valve assembly 100 reciprocates between the low/reverse apply circuit and the lock-up apply circuit operating positions, the mating valve bore is subject to mechanical wear by the reciprocating action of the solenoid switch valve discs 110, 112 which comprise a part of the switch valve assembly 100. This wear pattern in the surface of the valve bore causes the switch valve plugs or discs 110, 112 to become misaligned (i.e. cocked) upon axial shifting movement and often to lodge itself within the valve bore in the lock-up apply circuit operating position (FIG. 2).
U.S. Pat. No. 5,031,656 to Benford et al. teaches reciprocating valves in a fluid system of a Chrysler automatic transmission. This patent discloses a solenoid switch valve assembly including reciprocating valve plugs (see Benford et al., FIG. 11A) of a type, which are subject to the problems described hereinabove. The solenoid switch valve assembly of the present invention has been developed to improve upon this prior art design.
In this respect the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides a valve apparatus developed to permit both in tandem reciprocating movement of the valve plugs and also axial shifting movement of the plugs relative to each other to support the functions of such a solenoid switch valve assembly.